The overall objective of the program is to examine the mechanisms underlying the inflammatory reactions in the connective tissue diseases. In the current year, we hope (1) to ascertain whether rheumatoid synovial fluid and rheumatoid synovial tissue contains helper substances for B-cell stimulation and immunoglobulin synthesis; (2) to obtain further information about the mechanism for the deposition of immune complexes in cartilage in experimental antigen-induced arthritis; (3) to study the mechanism of the leukopenia in Felty's syndrome (rheumatoid arthritis with neutrogenia and splenomegaly); (4) to obtain further knowledge about the nature of a dialyzable macrophage migration inhibitory factor; (5) to study the mechanism of the autoimmune response in NZB-W hybrid mice; (6) to investigate the relationship between the renal disease and immunoglobulin deposition in the non-involved skin of patients with systemic lupus erythematosus (SLE); and (7) to study the comparative effects of cyclophosphamide and azathioprine on renal glomerular proliferation and fibrosis in the NZB-W hybrid mouse.